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nios2: System calls handling

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This patch adds support for system calls from userspaces. It uses the
asm-generic/unistd.h definitions with architecture spcific syscall.
The sys_call_table is just an array defined in a C file and it contains
pointers to the syscall functions.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
This commit is contained in:
Ley Foon Tan 2014-11-06 15:19:57 +08:00
parent 19f4c6b5af
commit 1000197d80
5 changed files with 270 additions and 0 deletions
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138
arch/nios2/include/asm/syscall.h Normal file
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/*
* Copyright Altera Corporation (C) <2014>. All rights reserved
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_NIOS2_SYSCALL_H__
#define __ASM_NIOS2_SYSCALL_H__
#include <linux/err.h>
#include <linux/sched.h>
static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
{
return regs->r2;
}
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
regs->r2 = regs->orig_r2;
regs->r7 = regs->orig_r7;
}
static inline long syscall_get_error(struct task_struct *task,
struct pt_regs *regs)
{
return regs->r7 ? regs->r2 : 0;
}
static inline long syscall_get_return_value(struct task_struct *task,
struct pt_regs *regs)
{
return regs->r2;
}
static inline void syscall_set_return_value(struct task_struct *task,
struct pt_regs *regs, int error, long val)
{
if (error) {
/* error < 0, but nios2 uses > 0 return value */
regs->r2 = -error;
regs->r7 = 1;
} else {
regs->r2 = val;
regs->r7 = 0;
}
}
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs, unsigned int i, unsigned int n,
unsigned long *args)
{
BUG_ON(i + n > 6);
switch (i) {
case 0:
if (!n--)
break;
*args++ = regs->r4;
case 1:
if (!n--)
break;
*args++ = regs->r5;
case 2:
if (!n--)
break;
*args++ = regs->r6;
case 3:
if (!n--)
break;
*args++ = regs->r7;
case 4:
if (!n--)
break;
*args++ = regs->r8;
case 5:
if (!n--)
break;
*args++ = regs->r9;
case 6:
if (!n--)
break;
default:
BUG();
}
}
static inline void syscall_set_arguments(struct task_struct *task,
struct pt_regs *regs, unsigned int i, unsigned int n,
const unsigned long *args)
{
BUG_ON(i + n > 6);
switch (i) {
case 0:
if (!n--)
break;
regs->r4 = *args++;
case 1:
if (!n--)
break;
regs->r5 = *args++;
case 2:
if (!n--)
break;
regs->r6 = *args++;
case 3:
if (!n--)
break;
regs->r7 = *args++;
case 4:
if (!n--)
break;
regs->r8 = *args++;
case 5:
if (!n--)
break;
regs->r9 = *args++;
case 6:
if (!n)
break;
default:
BUG();
}
}
#endif

25
arch/nios2/include/asm/syscalls.h Normal file
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/*
* Copyright Altera Corporation (C) 2013. All rights reserved
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef __ASM_NIOS2_SYSCALLS_H
#define __ASM_NIOS2_SYSCALLS_H
int sys_cacheflush(unsigned long addr, unsigned long len,
unsigned int op);
#include <asm-generic/syscalls.h>
#endif /* __ASM_NIOS2_SYSCALLS_H */

25
arch/nios2/include/uapi/asm/unistd.h Normal file
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/*
* Copyright (C) 2013 Altera Corporation
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#define sys_mmap2 sys_mmap_pgoff
/* Use the standard ABI for syscalls */
#include <asm-generic/unistd.h>
/* Additional Nios II specific syscalls. */
#define __NR_cacheflush (__NR_arch_specific_syscall)
__SYSCALL(__NR_cacheflush, sys_cacheflush)

53
arch/nios2/kernel/sys_nios2.c Normal file
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/*
* Copyright (C) 2013 Altera Corporation
* Copyright (C) 2011-2012 Tobias Klauser <tklauser@distanz.ch>
* Copyright (C) 2004 Microtronix Datacom Ltd.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/export.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
#include <asm/cacheflush.h>
#include <asm/traps.h>
/* sys_cacheflush -- flush the processor cache. */
asmlinkage int sys_cacheflush(unsigned long addr, unsigned long len,
unsigned int op)
{
struct vm_area_struct *vma;
if (len == 0)
return 0;
/* We only support op 0 now, return error if op is non-zero.*/
if (op)
return -EINVAL;
/* Check for overflow */
if (addr + len < addr)
return -EFAULT;
/*
* Verify that the specified address region actually belongs
* to this process.
*/
vma = find_vma(current->mm, addr);
if (vma == NULL || addr < vma->vm_start || addr + len > vma->vm_end)
return -EFAULT;
flush_cache_range(vma, addr, addr + len);
return 0;
}
asmlinkage int sys_getpagesize(void)
{
return PAGE_SIZE;
}

29
arch/nios2/kernel/syscall_table.c Normal file
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/*
* Copyright Altera Corporation (C) 2013. All rights reserved
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include <linux/syscalls.h>
#include <linux/signal.h>
#include <linux/unistd.h>
#include <asm/syscalls.h>
#undef __SYSCALL
#define __SYSCALL(nr, call) [nr] = (call),
void *sys_call_table[__NR_syscalls] = {
#include <asm/unistd.h>
};